BGP has a new friend – BGP-Based SDN

September 16, 2015

by Matt Conran Blog

BGP-Based SDN

The world of networking continues to evolve rapidly, with new technologies and approaches emerging to meet the growing demands of modern communication. Two such technologies, BGP (Border Gateway Protocol) and SDN (Software-Defined Networking), have gained significant attention for their impact on network flexibility and management. In this blog post, we will delve into the fascinating intersection of BGP and SDN, exploring how they work together to empower network administrators and optimize network operations.

Border Gateway Protocol (BGP) serves as the backbone of the internet, facilitating the exchange of routing information between networks. BGP enables dynamic routing, allowing routers to determine the best paths for data transmission based on various factors such as network policies, path preferences, and traffic conditions. It plays a crucial role in inter-domain routing, where multiple networks connect and exchange data.

Software-Defined Networking (SDN) introduces a paradigm shift in network management by decoupling the control plane from the data plane. In traditional networks, network devices such as switches and routers possess both control and data plane functionalities. SDN separates these functions, with a centralized controller managing the network's behavior and forwarding decisions. The data plane, consisting of switches and routers, simply follows the instructions provided by the controller.

When BGP and SDN converge, we unlock a new realm of network possibilities. SDN's centralized control and programmability complement BGP's routing capabilities, offering enhanced flexibility and control over network operations. By leveraging SDN controllers, network administrators can dynamically adjust BGP routing policies, optimize traffic flows, and respond to changing network conditions in real-time. This dynamic interaction between BGP and SDN empowers organizations to adapt their networks to ever-evolving requirements efficiently.

The combination of BGP and SDN brings forth several advantages and opens up exciting use cases. Network operators can implement traffic engineering techniques to optimize network paths, improve performance, and minimize congestion. They can also utilize SDN's programmability to automate BGP configuration and provisioning, reducing human errors and accelerating network deployment. Additionally, BGP-SDN integration facilitates the implementation of policies for traffic prioritization, security, and load balancing.

The convergence of BGP and SDN represents a powerful synergy that empowers network administrators to achieve unprecedented levels of flexibility, control, and efficiency. By combining BGP's robust routing capabilities with SDN's programmability and centralized management, organizations can adapt their networks swiftly to meet evolving demands. As the networking landscape continues to evolve, the BGP-SDN combination will undoubtedly play a pivotal role in shaping the future of network architecture.

Matt Conran

Highlights: BGP-Based SDN

Understanding BGP and SDN

1- BGP (Border Gateway Protocol) is a routing protocol used to exchange routing information between different networks on the internet. On the other hand, SDN is an architectural approach that separates the control plane from the data plane, allowing network administrators to centrally manage and configure networks through software.

2- BGP-based SDN combines the power of BGP routing with the flexibility and programmability of SDN. Network operators gain enhanced control, scalability, and agility in managing their networks by leveraging BGP as the control plane protocol in an SDN architecture. This marriage of BGP and SDN opens up new possibilities for network automation, policy-driven routing, and dynamic traffic engineering.

3- One critical advantage of BGP-based SDN is its ability to simplify network management. With centralized control and programmability, network operators can define policies and rules that govern their networks’ behavior.

4- This paves the way for efficient traffic engineering and the ability to respond dynamically to changing network conditions. Additionally, BGP-based SDN provides better scalability, allowing for the distribution of control plane functions across multiple controllers.

Knowledge Check: Prefer EBGP over iBGP

### What is eBGP?

eBGP, or External BGP, is used for routing between different autonomous systems (AS). An autonomous system is essentially a collection of IP networks and routers under the control of a single organization. eBGP is employed when these networks communicate with each other. Its primary purpose is to exchange routing information between these independent systems, ensuring data can travel from one network to another across the globe.

eBGP is characterized by its scalability and efficiency in handling large amounts of routing information. It operates by sending updates about network reachability, allowing each AS to determine the best path for data transmission. This makes it an indispensable tool for ISPs and large enterprises managing extensive network infrastructures.

### Understanding iBGP

On the other hand, iBGP, or Internal BGP, operates within a single autonomous system. Its purpose is to distribute routing information obtained from eBGP to all routers within the same AS. Unlike eBGP, which is concerned with external communication, iBGP ensures that all routers within the AS have a consistent view of the network topology.

iBGP is crucial for maintaining the integrity and efficiency of a network’s internal routing. It prevents routing loops and ensures that data packets find the most optimal path within the AS. Additionally, it works seamlessly with other interior gateway protocols like OSPF and IS-IS to enhance network performance.

### Key Differences Between eBGP and iBGP

While both eBGP and iBGP are integral parts of the BGP protocol, they serve distinct purposes and operate under different conditions. Here are some key differences:

1. **Operational Scope**: eBGP is used between different AS, whereas iBGP operates within a single AS.

2. **Path Selection**: eBGP selects routes based on the AS path, preferring shorter paths, while iBGP relies on the IGP metrics to determine the best route within the AS.

3. **Hop Count**: eBGP sessions are typically limited to a single hop, although multi-hop configurations are possible. iBGP sessions, however, can span multiple hops within the AS.

4. **Route Propagation**: eBGP routes are advertised to iBGP peers, but iBGP routes are not automatically advertised to other iBGP peers, requiring additional configuration to propagate routes.

### Practical Applications and Considerations

Network administrators must carefully consider their use of eBGP and iBGP when designing and managing network infrastructures. eBGP is essential for connecting to external networks and the internet, while iBGP ensures efficient internal routing. Balancing both is key to achieving optimal network performance and reliability.

When configuring BGP, it is also important to implement security measures to prevent attacks such as route hijacking. This includes using route filtering, authentication, and monitoring tools to safeguard network operations.

## The Role of BGP in Traditional Networking ##

BGP has long been the backbone of internet routing, enabling data to traverse global networks efficiently. Its robust, policy-driven approach allows for complex routing decisions based on a variety of factors like path attributes and network policies. However, traditional BGP setups can be rigid, often requiring manual configurations that are time-consuming and error-prone. This is where SDN comes into play, offering a more dynamic and programmable approach to network management.

## Integrating BGP with SDN: A New Era

The integration of BGP with SDN is not just about replacing old systems but augmenting them. By leveraging SDN’s centralized control and programmability, BGP-based SDN allows for automated policy changes and real-time network optimization. This results in a more agile network that can adapt to changing demands and conditions. The centralized SDN controller can dynamically manage BGP routes, reducing the complexity and improving the responsiveness of the network.

## BGP SDN Challenges

Despite its advantages, implementing BGP-based SDN is not without its challenges. Integrating SDN with existing BGP infrastructures can be complex and requires careful planning and execution. There is also the need for network professionals to acquire new skills and knowledge to effectively manage these advanced systems. Furthermore, ensuring compatibility between different SDN solutions and traditional network devices remains a critical consideration.

## Note: New Attack Surface

While BGP-based SDN holds immense potential, it also poses certain challenges. One of the primary concerns is the complexity of implementation and migration. Integrating BGP with SDN requires careful planning and coordination to ensure a smooth transition. Moreover, security and privacy considerations must be considered when deploying BGP-based SDN, as centralized control introduces new attack vectors that must be mitigated.

Critical Components of BGP SDN:

a. BGP Routing: BGP SDN leverages the BGP protocol to manage the routing decisions between different networks. This enables efficient and optimized routing and seamless communication across various domains.

b. SDN Controller: The SDN controller acts as the centralized brain of the network, providing a single point of control and management. It enables network administrators to define and enforce network policies, configure routing paths, and allocate network resources dynamically.

c. OpenFlow Protocol: BGP SDN uses the OpenFlow protocol to communicate between the SDN controller and the network switches. OpenFlow enables the controller to programmatically control the forwarding behavior of switches, resulting in greater flexibility and agility.

Example BGP Technology: IPv6 BGP

### IPv6 and BGP: A Synergistic Relationship

Transitioning to IPv6 doesn’t just mean more addresses; it means enhancing the operational capacity of BGP. IPv6 introduces features like simplified header formats and improved multicast routing, which can streamline the BGP process. This section will explore how IPv6 enhances BGP operations, offering benefits such as reduced latency, improved security, and better support for mobile networks.

### Challenges and Considerations in IPv6 BGP Deployment

Despite its advantages, the deployment of IPv6 within BGP is not without challenges. Network engineers face hurdles such as compatibility with existing IPv4 infrastructure, the complexity of dual-stack configurations, and the need for updated hardware and software. We’ll examine these challenges and provide insights into how organizations can navigate them to successfully implement IPv6 in their BGP configurations.

Benefits of BGP SDN:

a. Enhanced Flexibility: BGP SDN allows network administrators to tailor their network infrastructure to meet specific requirements. With centralized control, network policies can be easily modified or updated, enabling rapid adaptation to changing business needs.

b. Improved Scalability: Traditional network architectures often struggle to handle the growing demands of modern applications. BGP SDN provides a scalable solution by enabling dynamic allocation of network resources, optimizing traffic flow, and ensuring efficient bandwidth utilization.

c. Simplified Network Management: BGP SDN’s centralized management simplifies network operations. Network administrators can configure, monitor, and manage the entire network from a single interface, reducing complexity and improving overall efficiency.

Use Cases for BGP SDN:

a. Data Centers: BGP SDN is well-suited for data center environments, where rapid provisioning, scalability, and efficient workload distribution are critical. By leveraging BGP SDN, data centers can seamlessly integrate physical and virtual networks, enabling efficient resource allocation and workload migration.

b. Service Providers: BGP SDN allows service providers to offer their customers flexible and customizable network services. It enables the creation of virtual private networks, traffic engineering, and service chaining, resulting in improved service delivery and customer satisfaction.

BGP Technologies in BGP SDN

Understanding BGP Route Reflection

A – 🙂 BGP route reflection is a technique used to alleviate the burden of full-mesh connectivity in BGP networks. Traditionally, in a fully meshed BGP configuration, all routers must establish a direct peer-to-peer connection with every other router, resulting in complex and resource-intensive setups. Route reflection introduces a hierarchical approach that reduces the number of required connections, providing a more scalable alternative.

B – 🙂 Route reflectors act as centralized points within a BGP network and reflect and propagate routing information to other routers. They collect BGP updates from their clients and reflect them to other clients, ensuring a simplified and efficient distribution of routing information. Route reflectors maintain the overall consistency of the BGP network while reducing the number of required peer connections.

C- 🙂 To implement BGP route reflection, one or more routers within the network need to be configured as route reflectors. These route reflectors should be strategically placed to ensure efficient routing information dissemination. Clients, also known as non-route reflectors, establish peering sessions with the route reflectors and send their BGP updates to be reflected. Route reflector clusters can also be formed to provide redundancy and load balancing.

Understanding BGP Multipath

BGP multipath, short for Border Gateway Protocol multipath, is a feature that enables the use of multiple paths for traffic forwarding in a network. Traditionally, BGP selects a single best path based on attributes like AS path length, origin type, and MED (Multi-Exit Discriminator) value. However, with BGP multipath, multiple paths can be utilized simultaneously, distributing traffic across multiple links.

Enhanced Network Performance: BGP multipath optimizes network performance by load-balancing traffic using multiple paths. This helps avoid congestion on specific links and ensures efficient utilization of available bandwidth, resulting in faster and more reliable data transmission.

Improved Resilience: BGP multipath enhances network resilience by providing redundancy. In case of link failures or congestion, traffic can be automatically rerouted through alternative paths, minimizing downtime and ensuring continuous connectivity. This dramatically improves the overall reliability of the network infrastructure.

SDN and BGP

BGP SDN, or Border Gateway Protocol Software-Defined Networking, combines two powerful technologies: the Border Gateway Protocol (BGP) and Software-Defined Networking (SDN). BGP, a routing protocol, facilitates inter-domain routing, while SDN provides centralized control and programmability of the network. Together, they offer a dynamic and adaptable networking environment.

While Border Gateway Protocol (BGP) was initially designed to connect networks operated by different companies, such as transit service providers, providers of large-scale data centers discovered that it could be used for spine and leaf fabrics.

BGP can also be used as an SDN because it already runs on all routers. According to the diagram below, each router in the fabric is connected to an iBGP controller.

Augmented Model

After the iBGP sessions are established, the controller can read the entire topology to determine which path the flow should be pinned to and which flows should avoid the path over which the flow is passing.

An augmented model uses a centralized control plane that interacts directly with a distributed control plane (eBGP). Interestingly, the same protocol used to push policy (the southbound interface) is also used to discover and distribute topology and reachability information in this hybrid model implementation.

The Role of SDN

Before we start our journey on BGP SDN, let us first address what SDN means. The Software-Defined Networking (SDN) framework has a large and varied context. Multiple components, including the OpenFlow protocol, may or may not be used. Some evolving SDN use cases leverage the capabilities of the OpenFlow protocol, while others do not require it.

OpenFlow is only one of those protocols within the SDN architecture. This post addresses using the Border Gateway Protocol (BGP) as the transfer protocol between the SDN controller and forwarding devices, enabling BGP-based SDN, also known as BGP SDN.

BGP and OpenFlow

– BGP and OpenFlow are monolithic, meaning they are not used simultaneously. Integrating BGP to SDN offers several use cases, such as DDoS mitigation, exception routing, forwarding optimizations, graceful shutdown, and integration with legacy networks.

– Some of these use cases are available using OpenFlow Traffic Engineering; others, like graceful shutdown and integration with the legacy network, are easier to accomplish with BGP SDN.

– When BGP and OpenFlow are combined, they create a powerful synergy that enhances network control and performance. BGP provides the foundation for inter-domain routing and connectivity, while OpenFlow facilitates granular traffic engineering within a domain.

– Together, they enable network administrators to fine-tune routing decisions, balance traffic across multiple paths, and enforce quality of service (QoS) policies.

BGP Add Path Feature

The BGP Add Path feature is designed to address the limitations of traditional BGP routing, where only the best path to a destination is advertised. With Add Path, BGP routers can advertise multiple paths to a destination network, providing increased routing options and allowing for more efficient traffic engineering.

Introducing the Add Path feature brings several benefits to network administrators and service providers. Firstly, it enables better load balancing and traffic distribution across multiple paths, leading to optimized network utilization. Additionally, it enhances network resiliency by providing alternative paths in case of link failures or congestion.

Before you proceed, you may find the following post helpful:

BGP-Based SDN

What is BGP?

What is the BGP protocol in networking? Border Gateway Protocol (BGP) is the routing protocol under the Exterior Gateway Protocol (EGP) category. In addition, we have separate protocols, which are Interior Gateway Protocols (IGPs). However, IGP can have some disadvantages.

Firstly, policies are challenging to implement with an IGP because of the need for more flexibility. Usually, a tag is the only tool available that can be problematic to manage and execute on a large-scale basis. In the age of increasingly complex networks in both architecture and services, BGP presents a comprehensive suite of knobs to deal with complex policies, such as the following:

• Communities

• AS_PATH filters

• Local preference

• Multiple exit discriminator (MED

Highlighting BGP-based SDN

BGP-based SDN involves two main solution components that may be integrated into several existing BGP technologies. First, we have an SDN controller component that speaks BGP and decides what needs to be done. Second, we have a BGP originator component that sends BGP updates to the SDN controller and other BGP peers. For example, the controller could be a BGP software package running on Open Daylight. BGP originators are Linux daemons or traditional proprietary vendor devices running the BGP stack.

Creating an SDN architecture

To create the SDN architecture, these components are integrated with existing BGP technologies, such as BGP FlowSpec (RFC 5575), L3VPN (RFC4364), EVPN (RFC 7432), and BGP-LS. BGP FlowSpec distributes forwarding entries, such as ACL and PBR, to devices’ TCAMs. L3VPN and EVPN offer the mechanism to integrate with legacy networks and service insertion. BGP-LS extracts IGP network topology information and passes it to the SDN controller via BGP updates.

**Central policy, visibility, and control**

Introducing BGP into the SDN framework does not mean a centralized control plane. We still have a central policy, visibility, and control, but this is not a centralized control plane. A centralized control plane would involve local control plane protocols establishing adjacencies or other ties to the controller. In this case, the forwarding devices outright require the controller to forward packets; forwarding functionality is limited when the controller is down.

If the BGP SDN controller acts as a BGP route reflector, all announcements go to the controller, but the network runs fine without it. The controller is just adding value to the usual forwarding process. BGP-based SDN architecture augments the network; it does not replace it.

Decentralizing the control plane is the only way; look at Big Switch and NEC’s SDN design changes over the last few years. Centralized control planes cannot scale.

Why use BGP?

BGP is well-understood and field-tested. It has been extended on many occasions to carry additional types of information, such as MAC addresses and labels. Technically, BGP can be used as a replacement for Label Distribution Protocol (LDP) in an MPLS core. Labels can be assigned to IPv6 prefixes (6PE) and labeled switched across an IPv4-only MPLS core.

BGP is very extensible. It started with IPv4 forwarding, and address families were added for multicast and VPN traffic. Using multiple addresses inside a single BGP process was widely accepted and implemented as a core technology. The entire Internet is made up of BGP, and it carries over 500,000 prefixes. It’s very scalable and robust. Some MPLS service providers are carrying over 1 million customer routes.

The use of open-source BGP daemons

There are many high-quality open-source BGP daemons available. Quagga is one of the most popular, and its quality has improved since it adopted Cumulus and Google. Quagga is a routing suite that provides IGP support for IS-IS and OSPF. Also, a BIRD daemon is available. The implementation is based around Internet exchange points as the route server element. BIRD is currently carrying over 100,000 prefixes.

Using BGP-based SDN on an SDN controller integrates easily with your existing network. You don’t have to replace any existing equipment, deploy the controller, and implement the add-on functionality that BGP SDN offers. It enables a preferred step-by-step migration approach, not a risky big bang OpenFlow deployment.

IGP to the controller?

Why not run OSPF or ISIS to the controller? IS-IS is extendable with TLVs and, too, can carry a variety of information. The real problem is not extensibility but the lack of trust and policy control. IGP extension to the SDN controller with few controls could present a problem. OSPF sends LSA packets; there is no input filter. BGP is designed with policy control in mind and acts as a filter by implementing controls on individual BGP sessions.

BGP offers control on the network side and predicts what the controller can do. For example, the blast radius is restricted if the controller encounters a bug or is compromised. BGP also provides excellent policy mechanisms between the SDN controller and physical infrastructure.

Example IGP Technology: IPv6 OSPFv3

**The Evolution from OSPFv2 to OSPFv3**

OSPFv2, originally developed for IPv4, has been a reliable protocol for decades. However, with the transition to IPv6, a more robust solution was needed to handle the complexities of the new addressing scheme. Enter OSPFv3. This updated version retains the core principles of OSPFv2, such as using link-state routing and the Dijkstra algorithm, but introduces significant improvements. OSPFv3 supports larger address spaces, offers better security options, and is more flexible in its deployment, making it a natural choice for IPv6 networks.

**Key Features of OSPFv3**

One of the standout features of OSPFv3 is its address family support, which allows for the simultaneous routing of both IPv4 and IPv6. This dual capability is essential for networks transitioning between the two protocols. Additionally, OSPFv3 enhances security through the use of IPsec for authentication and confidentiality, addressing the vulnerabilities present in OSPFv2. The protocol also introduces a simplified packet structure, reducing overhead and increasing efficiency in data transmission.

**Implementing OSPFv3 in Your Network**

For network administrators, implementing OSPFv3 can seem daunting, but the benefits far outweigh the challenges. The protocol’s compatibility with both IPv4 and IPv6 means that it can be integrated into existing infrastructure with minimal disruption. When setting up OSPFv3, it’s crucial to ensure that all routers in the network are configured correctly to prevent routing loops and ensure seamless data flow. Regularly updating network configurations and monitoring performance can help maintain optimal operation.

Introducing BGP-LS

SDN requires complete topology visibility. The picture is incomplete if some topology information is hidden in IGP and other NLRIs in BGP. If you have an existing IGP, how do you propagate this information to the BGP controller? Border Gateway Protocol Link-State (BGP-LS) is cleaner than establishing an IGP peering relationship with the SDN controller.

BGP-LS extracts network topology information and updates it to the BGP controller. Once again, BGPv4 is extended to provide the capability to include the new Network Layer Reachability Information (NLRI) encoding format. It sends information from IS-IS or OSPF topology database through BGP updates to the SDN controller. BGP-LS can configure the session to be unidirectional and stop incoming updates to enhance security between the physical and SDN worlds.

SDN controller cannot leak information back

As a result, the SDN controller cannot leak information back into the running network. BGP-LS is a relatively new concept. It focuses on the mechanism to export IGP information and does not describe how the SDN controller can use it. Once the controller has the complete topology information, it may be integrated with traffic engineers and external path computing solutions to interact with information usually only carried by an IGP database.

For example, the Traffic Engineering Database (TED), built by ISIS and OSPF-TE extensions, is typically distributed by IGPs within the network. Previously, each node maintained its own TED, but now, this can be exported to a BGP RR SDN application for better visibility.

BGP scale-out architectures

SDN controller will always become the scalability bottleneck. It can scale better when it’s not participating in data plane activity, but eventually, it will reach its limits. Every controller implementation eventually hits this point. The only way to grow is to scale out.

Reachability and policy information is synchronized between individual controllers. For example, reachability information can be transferred and synchronized with MP-BGP, L3VPN for IP routing, or EVPN for layer-2 forwarding.

Utilizing BGP between controllers offers additional benefits. Each controller can be placed in a separate availability zone, and tight BGP policy controls are implemented on BGP sessions connecting those domains, offering a clean failure domain separation.

An error in one available zone is not propagated to the next available zone. BGP is a very scalable protocol, and the failure domains can be as large as you want, but the more significant the domain, the longer the convergence times. Adjust the size of failure domains to meet scalability and convergence requirements.

Final Points: BGP-Based SDN

To appreciate the value of BGP-based SDN, it is essential to understand its components. BGP, the protocol that powers the internet by determining the best paths for data transmission, offers unparalleled scalability and stability. On the other hand, SDN introduces a dynamic and flexible approach to network management by decoupling the control plane from the data plane. When combined, BGP’s robust path selection and SDN’s centralized control create a network environment that is both resilient and adaptive to changing demands.

One of the primary advantages of integrating BGP with SDN is its ability to enhance network visibility and control. With centralized management, network administrators can implement comprehensive policies that optimize traffic flow, reduce latency, and improve security. Additionally, BGP-based SDN facilitates rapid deployment of new services and applications, enabling businesses to respond swiftly to market changes. This synergy also simplifies network troubleshooting and maintenance, leading to reduced operational costs and increased uptime.

BGP-based SDN is not just a theoretical concept; it is being actively implemented across various sectors. In data centers, it enables efficient resource utilization and supports the seamless scaling of services. Telecommunications companies leverage BGP-based SDN for efficient routing and traffic engineering, ensuring optimal performance and reliability. Furthermore, enterprises adopting hybrid cloud environments benefit from the enhanced connectivity and simplified management that this approach offers, allowing them to maintain competitive advantage in a digital-first world.

Summary: BGP-Based SDN

In today’s rapidly evolving technological landscape, software-defined networking (SDN) has emerged as a groundbreaking approach to network management. One of the key components within the realm of SDN is the Border Gateway Protocol (BGP). In this blog post, we delved into the world of BGP SDN, exploring its significance, functionality, and how it transforms traditional networking architectures.

Understanding BGP

BGP, or Border Gateway Protocol, is a routing protocol that facilitates the exchange of routing information between different autonomous systems (AS). It plays a crucial role in determining the optimal path for data packets to traverse across the internet. Unlike other routing protocols, BGP operates on a policy-based routing model, allowing network administrators to have granular control over traffic flow and network policies.

The Evolution of SDN

To comprehend the importance of BGP SDN, it is essential to understand the evolution of software-defined networking. SDN revolutionizes traditional network architectures by decoupling the control plane from the underlying physical infrastructure. This separation enables centralized network control, programmability, and dynamic configuration, enhancing flexibility and scalability.

BGP in the SDN Paradigm

Within the SDN framework, BGP plays a pivotal role in interconnecting different SDN domains, providing a scalable and flexible solution for routing between virtual networks. By incorporating BGP into the SDN architecture, organizations can achieve dynamic network provisioning, traffic engineering, and efficient handling of network policy changes.

Benefits of BGP SDN

The integration of BGP within the SDN paradigm brings forth numerous benefits. Firstly, it enables seamless interoperability between SDN and traditional networking environments, ensuring a smooth transition towards software-defined infrastructures. Additionally, BGP SDN empowers network administrators with enhanced control and visibility, simplifying the management of complex network topologies and policies.

Conclusion:

In conclusion, BGP SDN represents a significant milestone in the networking industry. Its ability to merge the power of BGP with the flexibility of software-defined networking opens new horizons for network management. By embracing BGP SDN, organizations can achieve greater agility, scalability, and control over their networks, ultimately leading to more efficient and adaptable infrastructures.

VIPTELA SD-WAN – WAN Segmentation

August 11, 2015

by Matt Conran Blog

VIPTELA SD-WAN

Problem Statement

WAN edge networks sit too far from business logic and are built, and designed with limited application and business flexibility. On the other hand, applications sit closer to business logic. It’s time for networking to bridge this gap using policies and business logic-aware principles. For additional information on WAN, challenges proceed to this SD WAN tutorial.

Traditional Segmentation

Network segmentation is defined as a portion of the network that is separated from the rest. Segmentation can be physical or logical. Physical segmentation involves complete isolation at a device and link level. Some organizations require the physical division of individual business units for security, political, or other reasons. At a basic level, logical segmentation begins with VLAN boundaries at Layer 2. VLAN consists of a group of devices that communicate as if they were connected to the same wire. As VLANs are logical and not physical connections, they are flexible and can span multiple devices.

While VLANs provide logical separation at Layer 2, virtual routing and forwarding (VRF) instances provide separation at Layer 3. Layer 2 VLAN can now map to Layer 3 VRF instances. However, every VRF has a separate control plane and configuration completed on a hop-by-hop basis. Individual VRFs with separate control planes from individual routing protocol neighbor relationships, hamper router performance.

MPLS/VPNs overcome hop-by-hop configurations to allow segmentation. This enables physically divided business units to be logically divided without the need for individual hop-by-hop VPN configurations throughout the network. Instead, only the PE edge routers carry VPN information. This supports a variety of topologies such as hub and spoke, partial mesh, or any to any connectivity. While MPLS/VPNs have their benefits, they also introduce a unique set of challenges.

MPLS Challenges

MPLS topologies, once provisioned, are difficult to modify. This is due to the fact that all the impacted PE routers have to be re-provisioned with each new policy change. In this way, MPLS topologies are similar to the brick foundation of a house. Once the foundation is laid, it’s hard to make changes to the original structure without starting over.

Most modifications to VPN site topologies must go through an additional design phase. If a Wide Area Network (WAN) is outsourced to a carrier, it would require service provider intervention with additional design & provisioning activities. A simple task such as mapping application subnets to new or existing RT may involve onsite consultants, new high-level design, and configuration templates which would have to be applied by provisioning teams. Service provider provisioning and design activities are not free and usually have long lead times.

Some flexible Edge MPLS designs do exist. For example, community tagging and matching. During the design phase, the customer and service provider agree on predefined communities. Once these are set by the customer (attached to a prefix) they are matched by the provider to perform a certain type of traffic engineering (TE).

While community tagging and matching do provide some degree of flexibility and are commonly used, it remains a fixed, predefined configuration. Any subsequent design changes may still require service provider intervention.

Applications Must Fit A Certain Topology

The model forces applications to fit into a network topology that is already built and designed. It lacks the flexibility for the network to keep up with changing business needs. What’s needed is a way to map application requirements to the network. Applications are exploding and each has a variety of operational and performance requirements, which should be met in isolation.

Viptela SD-WAN & Topologies Per Application

By moving from hardware and diverse control planes to software & unified control planes at the WAN edge, SD-WAN evolves the fixed network approach. It abstracts the details of WAN; allowing application-independent topologies. SD-WAN provides segmentation between traffic sets and could be a good way to help create on-demand applications. Essentially, creating multiple on-demand topologies per application or group of applications. Each application can have its own topology and dynamically changing policies which are managed by a central controller.

The application controls the network design.

SD-WAN - Application flows — SD-WAN – Application flows

In SD-WAN, the central controller is hosted and managed by the customer, not a service provider. This enables the WAN to be segmented for each application at the customer’s discretion. For example, PCI traffic can be transported using an overlay specifically designed for compliance via Provider A. Meanwhile, ATM traffic can travel over the same provider network but using an overlay specifically designed for ATM. Meanwhile, each overlay can have different performance characteristics for path failover so that if the network does not reach a certain round-trip time (RTT) metric, traffic can reroute over another path. The customer has complete control over what application goes where and has the power to change policies on the fly.

The SDN controller, which acts as the brain, can set different applications to run over different paths based on business requirements and performance SLAs, not on a fixed topology. Each topology is segmented from the others and applications can share or have independent on-demand topologies. SD-WAN dramatically accelerates the time it takes to adapt the network to changing business needs.

SD-WAN Topologies

The network topologies can be depicted either physically or logically. Common topologies such as Star, Mesh, Full, and Ring are categorized under a centralized or decentralized function. In a physical world, these topologies are fixed and cannot be automatically changed. Logical topologies may also be hindered by physical device footprints.

In contrast, SD-WAN fully supports the coexistence of multiple application topologies regardless of existing physical footprints. For example, Lync message and video subscriptions may require different path topologies with separate SLAs. Messages may travel over low-cost links while video requires lower latency transports.

SD-WAN can flexibly cater to the needs of any type of application. In retail environments, store-specific applications may require a hub and spoke topology for authentication or security requirements. Surveillance systems may require full mesh topology. Guest Wi-fi may require local Internal access compared to normal user traffic that is scrubbed via a hub site. This per-application topology gives designers better control over the network. Viptela SD-WAN endpoints support multiple logical segments (regardless of the existing physical network), each of which can use a unique topology (full mesh, hub and spoke, ring) and be managed via its own policy.

Viptela SD-WAN: Predictable Application Performance

Obtaining predictable services is achieved by understanding the per-application requirements and routing appropriately.

Traditional MPLS WANs, offer limited fabric visibility. For example, providers allow enterprises to perform traceroute and pings, but bits-per-second is a primitive and unreliable method for measuring end-to-end application performance. Instead, WANs should be monitored at multiple layers, not just at the packet layer.

If a service provider is multiple autonomous systems (AS) away and experiencing performance problems, these cannot be addressed and detected using traditional distance-vector methods. This makes it impossible to route around problems and detect transitory oscillations. If errors on a transit path exist, a way must exist to penalize those paths.

Currently, there’s no way to detect when a remote network on the Internet is experiencing brownouts. Since the routing protocol is still operating, the best path does not change as neighbors might still be up. Routing should exist at the transport and application layer, and monitor both application flows and transactions. SD-WAN provides this function and delivers visibility at the device, transport, and application layer for insight into how the network is performing at any given time. This makes it possible to react to transitory failures before they can impact users.

“This post is sponsored by Viptela, an SD-WAN company. All thoughts and opinions expressed are the authors”

WAN SDN

May 11, 2015

by Matt Conran Blog

WAN SDN

In today's fast-paced digital world, organizations constantly seek ways to optimize their network infrastructure for improved performance, scalability, and cost efficiency. One emerging technology that has gained significant traction is WAN Software-Defined Networking (SDN). By decoupling the control and data planes, WAN SDN provides organizations unprecedented flexibility, agility, and control over their wide area networks (WANs). In this blog post, we will delve into the world of WAN SDN, exploring its key benefits, implementation considerations, and real-world use cases.

WAN SDN is a network architecture that allows organizations to manage and control their wide area networks using software centrally. Traditionally, WANs have been complex and time-consuming to configure, often requiring manual network provisioning and management intervention. However, with WAN SDN, network administrators can automate these tasks through a centralized controller, simplifying network operations and reducing human errors.

Enhanced Agility: WAN SDN empowers network administrators with the ability to quickly adapt to changing business needs. With programmable policies and dynamic control, organizations can easily adjust network configurations, prioritize traffic, and implement changes without the need for manual reconfiguration of individual devices.

Improved Scalability: Traditional wide area networks often face scalability challenges due to the complex nature of managing numerous remote sites. WAN SDN addresses this issue by providing centralized control, allowing for streamlined network expansion, and efficient resource allocation.

Optimal Resource Utilization: WAN SDN enables organizations to maximize their network resources by intelligently routing traffic and dynamically allocating bandwidth based on real-time demands. This ensures that critical applications receive the necessary resources while minimizing wastage.

Multi-site Enterprises: WAN SDN is particularly beneficial for organizations with multiple branch locations. It allows for simplified network management across geographically dispersed sites, enabling efficient resource allocation, centralized security policies, and rapid deployment of new services.

Cloud Connectivity: WAN SDN plays a crucial role in connecting enterprise networks with cloud service providers. It offers seamless integration, secure connections, and dynamic bandwidth allocation, ensuring optimal performance and reliability for cloud-based applications.

Service Providers: WAN SDN can revolutionize how service providers deliver network services to their customers. It enables the creation of virtual private networks (VPNs) on-demand, facilitates network slicing for different tenants, and provides granular control and visibility for service-level agreements (SLAs).

WAN SDN represents a paradigm shift in wide area network management. Its ability to centralize control, enhance agility, and optimize resource utilization make it a game-changer for modern networking infrastructures. As organizations continue to embrace digital transformation and demand more from their networks, WAN SDN will undoubtedly play a pivotal role in shaping the future of networking.

Matt Conran

Highlights: WAN SDN

Discussing WAN SDN

1: – ) Traditional WANs have long been plagued by various limitations, such as complexity, lack of agility, and high operational costs. These legacy networks typically rely on manual configurations and proprietary hardware, making them inflexible and time-consuming. SDN brings a paradigm shift to WANs by decoupling the network control plane from the underlying infrastructure. With centralized control and programmability, SDN enables network administrators to manage and orchestrate their WANs through a single interface, simplifying network operations and promoting agility.

2: – ) At its core, WAN SDN separates the control plane from the data plane, allowing network administrators to manage network traffic dynamically and programmatically. This separation leads to more efficient network management, reducing the complexity associated with traditional network infrastructures. With WAN SDN, businesses can optimize traffic flow, enhance security, and reduce operational costs by leveraging centralized control and automation.

3: – ) One of the key advantages of SDN in WANs is its inherent flexibility and scalability. With SDN, network administrators can dynamically allocate bandwidth, reroute traffic, and prioritize applications based on real-time needs. This level of granular control allows organizations to optimize their network resources efficiently and adapt to changing demands.

4: – ) SDN brings enhanced security features to WANs through centralized policy enforcement and monitoring. By abstracting network control, SDN allows for consistent security policies across the entire network, minimizing vulnerabilities and ensuring better threat detection and mitigation. Additionally, SDN enables rapid network recovery and failover mechanisms, enhancing overall resilience.

**Key Benefits of WAN SDN**

1. **Scalability and Flexibility**: WAN SDN enables networks to adapt quickly to changing demands without the need for significant hardware investments. This flexibility is crucial for organizations looking to scale their operations efficiently.

2. **Improved Network Performance**: By optimizing traffic routing and prioritizing critical applications, WAN SDN ensures that networks operate at peak performance levels. This capability is particularly beneficial for businesses with high bandwidth demands.

3. **Enhanced Security**: WAN SDN allows for the implementation of robust security measures, including automated threat detection and response. This proactive approach to security helps protect sensitive data and maintain compliance with industry regulations.

Application Challenges

Compared to a network-centric model, business intent-based WAN networks have great potential. By using a WAN architecture, applications can be deployed and managed more efficiently. However, application services topologies must replace network topologies. Supporting new and existing applications on the WAN is a common challenge for network operations staff. Applications such as these consume large amounts of bandwidth and are extremely sensitive to variations in bandwidth quality. Improving the WAN environment for these applications is more critical due to jitter, loss, and delay.

WAN SLA

In addition, cloud-based applications such as Enterprise Resource Planning (ERP) and Customer Relationship Management (CRM) are increasing bandwidth demands on the WAN. As cloud applications require increasing bandwidth, provisioning new applications and services is becoming increasingly complex and expensive. In today’s business environment, WAN routing and network SLAs are controlled by MPLS L3VPN service providers. As a result, they are less able to adapt to new delivery methods, such as cloud-based and SaaS-based applications.

These applications could take months to implement in service providers’ environments. These changes can also be expensive for some service providers, and some may not be made at all. There is no way to instantiate VPNs independent of underlying transport since service providers control the WAN core. Implementing differentiated service levels for different applications becomes challenging, if not impossible.

WAN SDN Technology: DMVPN

DMVPN is a Cisco-developed solution that enables the creation of virtual private networks over public or private networks. Unlike traditional VPNs that require point-to-point connections, DMVPN utilizes a hub-and-spoke architecture, allowing for dynamic and scalable network deployments. DMVPN simplifies network management and reduces administrative overhead by leveraging multipoint GRE tunnels.

– Multipoint GRE Tunnels: At the core of DMVPN lies the concept of multipoint GRE tunnels. These tunnels create a virtual network, connecting multiple sites while encapsulating packets in GRE headers. This enables efficient traffic routing between sites, reducing the complexity and overhead associated with traditional point-to-point VPNs.

– Next-Hop Resolution Protocol (NHRP): NHRP plays a crucial role in DMVPN by dynamically mapping tunnel IP addresses to physical addresses. It allows for the efficient resolution of next-hop information, eliminating the need for static routes. NHRP also enables on-demand tunnel establishment, improving scalability and reducing administrative overhead.

– IPsec Encryption: DMVPN utilizes IPsec encryption to ensure secure communication over the VPN. IPsec provides confidentiality, integrity, and authentication of data, making it ideal for protecting sensitive information transmitted over the network. With DMVPN, IPsec is applied dynamically per-tunnelly, enhancing flexibility and scalability.

DMVPN over IPSec

Understanding DMVPN & IPSec

IPsec, a widely adopted security protocol, is integral to DMVPN deployments. It provides the cryptographic framework necessary for securing data transmitted over the network. By leveraging IPsec, DMVPN ensures the transmitted information’s confidentiality, integrity, and authenticity, protecting sensitive data from unauthorized access and tampering.

Firstly, the dynamic mesh topology eliminates the need for complex hub-and-spoke configurations, simplifying network management and reducing administrative overhead. Additionally, DMVPN’s scalability enables seamless integration of new sites and facilitates rapid expansion without compromising performance. Furthermore, the inherent flexibility ensures optimal routing, load balancing, and efficient bandwidth utilization.

Example WAN Techniques:

Understanding Virtual Routing and Forwarding

VRF is a technology that enables the creation of multiple virtual routing tables within a single physical router. Each VRF instance acts as an independent router with its routing table, interfaces, and forwarding decisions. This separation allows different networks or customers to coexist on the same physical infrastructure while maintaining complete isolation.

One critical advantage of VRF is its ability to provide network segmentation. By dividing a physical router into multiple VRF instances, organizations can isolate their networks, ensuring that traffic from one VRF does not leak into another. This enhances security and provides a robust framework for multi-tenancy scenarios.

Use Cases for VRF

VRF finds application in various scenarios, including:

1. Service Providers: VRF allows providers to offer their customers virtual private network (VPN) services. Each customer can have their own VRF, ensuring their traffic remains separate and secure.

2. Enterprise Networks: VRF can segregate different organizational departments, creating independent virtual networks.

3. Internet of Things (IoT): With the proliferation of IoT devices, VRF can create separate routing domains for different IoT deployments, improving scalability and security.

Understanding Policy-Based Routing

Policy-based Routing, at its core, involves manipulating routing decisions based on predefined policies. Unlike traditional routing protocols that rely solely on destination addresses, PBR considers additional factors such as source IP, ports, protocols, and even time of day. By implementing PBR, network administrators gain flexibility in directing traffic flows to specific paths based on specified conditions.

The adoption of Policy Based Routing brings forth a multitude of benefits. Firstly, it enables efficient utilization of network resources by allowing administrators to prioritize or allocate bandwidth for specific applications or user groups. Additionally, PBR enhances security by allowing traffic redirection to dedicated firewalls or intrusion detection systems. Furthermore, PBR facilitates load balancing and traffic engineering, ensuring optimal performance across the network.

Implementing Policy-Based Routing

To implement PBR, network administrators must follow a series of steps. Firstly, the traffic classification criteria are defined by specifying the match criteria based on desired conditions. Secondly, create route maps that outline the actions for matched traffic. These actions may include altering the next-hop address, setting specific Quality of Service (QoS) parameters, or redirecting traffic to a different interface. Lastly, the route maps should be applied to the appropriate interfaces or specific traffic flows.

Example SD WAN Product: Cisco Meraki

**Seamless Cloud Management**

One of the standout features of Cisco Meraki is its seamless cloud management. Unlike traditional network systems, Meraki’s cloud-based platform allows IT administrators to manage their entire network from a single, intuitive dashboard. This centralization not only simplifies network management but also provides real-time visibility and control over all connected devices. With automatic updates and zero-touch provisioning, businesses can ensure their network is always up-to-date and secure without the need for extensive manual intervention.

**Cutting-Edge Security Features**

Security is at the core of Cisco Meraki’s suite of products. With cyber threats becoming more sophisticated, Meraki offers a multi-layered security approach to protect sensitive data. Features such as Advanced Malware Protection (AMP), Intrusion Prevention System (IPS), and secure VPNs ensure that the network is safeguarded against intrusions and malware. Additionally, Meraki’s security appliances are designed to detect and mitigate threats in real-time, providing businesses with peace of mind knowing their data is secure.

**Scalability and Flexibility**

As businesses grow, so do their networking needs. Cisco Meraki’s scalable solutions are designed to grow with your organization. Whether you are expanding your office space, adding new branches, or integrating more IoT devices, Meraki’s flexible infrastructure can easily adapt to these changes. The platform supports a wide range of devices, from access points and switches to security cameras and mobile device management, making it a comprehensive solution for various networking requirements.

**Enhanced User Experience**

Beyond security and management, Cisco Meraki enhances the user experience by ensuring reliable and high-performance network connectivity. Features such as intelligent traffic shaping, load balancing, and seamless roaming between access points ensure that users enjoy consistent and fast internet access. Furthermore, Meraki’s analytics tools provide insights into network usage and performance, allowing businesses to optimize their network for better efficiency and user satisfaction.

Performance at the WAN Edge

Understanding Performance-Based Routing

Performance-based routing is a dynamic approach to network traffic management that prioritizes route selection based on real-time performance metrics. Instead of relying on traditional static routing protocols, performance-based routing algorithms assess the current conditions of network paths, such as latency, packet loss, and available bandwidth, to make informed routing decisions. By dynamically adapting to changing network conditions, performance-based routing aims to optimize traffic flow and enhance overall network performance.

The adoption of performance-based routing brings forth a multitude of benefits for businesses.

1- Firstly, it enhances network reliability by automatically rerouting traffic away from congested or underperforming paths, minimizing the chances of bottlenecks and service disruptions.

2- Secondly, it optimizes application performance by intelligently selecting the best path based on real-time network conditions, thus reducing latency and improving end-user experience. A

3- Additionally, performance-based routing allows for efficient utilization of available network resources, maximizing bandwidth utilization and cost-effectiveness.

Implementation Details:

Implementing performance-based routing requires a thoughtful approach. Firstly, businesses must invest in monitoring tools that provide real-time insights into network performance metrics. These tools can range from simple latency monitoring to more advanced solutions that analyze packet loss and bandwidth availability.

Once the necessary monitoring infrastructure is in place, configuring performance-based routing algorithms within network devices becomes the next step. This involves setting up rules and policies that dictate how traffic should be routed based on specific performance metrics.

Lastly, regular monitoring and fine-tuning performance-based routing configurations are essential to ensure optimal network performance.

WAN Performance Parameters

TCP Performance Parameters

TCP (Transmission Control Protocol) is the backbone of modern Internet communication, ensuring reliable data transmission across networks. Behind the scenes, TCP performance is influenced by several key parameters that can significantly impact network efficiency.

TCP performance parameters govern how TCP behaves in various network conditions. These parameters can be fine-tuned to adapt TCP’s behavior to specific network characteristics, such as latency, bandwidth, and congestion. By adjusting these parameters, network administrators and system engineers can optimize TCP performance for better throughput, reduced latency, and improved overall network efficiency.

Congestion Control Algorithms: Congestion control algorithms are crucial in TCP performance. They monitor network conditions, detect congestion, and adjust TCP’s sending rate accordingly. Popular algorithms like Reno, Cubic, and BBR implement different strategies to handle congestion, balancing fairness and efficiency. Understanding these algorithms and their impact on TCP behavior is essential for maintaining a stable and responsive network.

Window Size and Bandwidth Delay Product: The window size parameter, often called the congestion window, determines the amount of data that can be sent before receiving an acknowledgment. The bandwidth-delay product should set the window size, a value calculated by multiplying the available bandwidth with the round-trip time (RTT). Adjusting the window size to match the bandwidth-delay product ensures optimal data transfer and prevents underutilization or overutilization of network resources.

Maximum Segment Size (MSS): The Maximum Segment Size is another TCP performance parameter defining the maximum amount of data encapsulated within a single TCP segment. By carefully configuring the MSS, it is possible to reduce packet fragmentation, enhance data transmission efficiency, and mitigate issues related to network overhead.

Selective Acknowledgment (SACK): Selective Acknowledgment is a TCP extension that allows the receiver to acknowledge out-of-order segments and provide more precise information about the received data. Enabling SACK can improve TCP performance by reducing retransmissions and enhancing the overall reliability of data transmission.

Understanding TCP MSS

TCP MSS refers to the maximum amount of data encapsulated within a single TCP segment. It represents the most significant data payload that can be transmitted without fragmentation. By limiting the segment size, TCP aims to prevent excessive overhead and ensure efficient data transmission across networks.

Several factors influence the determination of TCP MSS. One crucial aspect is the underlying network infrastructure’s Maximum Transmission Unit (MTU). The MTU represents the maximum packet size that can be transmitted over the network without fragmentation. TCP MSS must be set to a value equal to or lower than the MTU to avoid fragmentation and subsequent performance degradation.

Path MTU Discovery (PMTUD) is a mechanism TCP employs to dynamically determine the optimal MSS value for a given network path. By exchanging ICMP messages with routers along the path, TCP can ascertain the MTU and adjust the MSS accordingly. PMTUD helps prevent packet fragmentation and ensures efficient data transmission across network segments.

The TCP MSS value directly affects network performance. A smaller MSS can increase overhead due to more segments and headers, potentially reducing overall throughput. On the other hand, a larger MSS can increase the risk of fragmentation and subsequent retransmissions, impacting latency and overall network efficiency. Striking the right balance is crucial for optimal performance.

Example WAN Technology: DMVPN Phase 3

Understanding DMVPN Phase 3

DMVPN Phase 3 builds upon the foundation of its predecessors, bringing forth even more advanced features. This section will provide an overview of DMVPN Phase 3, highlighting its main enhancements, such as increased scalability, simplified configuration, and enhanced security protocols.

One of the standout features of DMVPN Phase 3 is its scalability. This section will explain how DMVPN Phase 3 allows organizations to effortlessly add new sites to the network without complex manual configurations. By leveraging multipoint GRE tunnels, DMVPN Phase 3 offers a dynamic and flexible solution that can easily accommodate growing networks.

Example WAN Technology: FlexVPN Site-to-Site Smart Defaults

Understanding FlexVPN Site-to-Site Smart Defaults

FlexVPN Site-to-Site Smart Defaults is a powerful feature that simplifies site-to-site VPN configuration and deployment process. Providing pre-defined templates and configurations eliminates the need for manual configuration, reducing the chances of misconfigurations or human errors. This feature ensures a secure and reliable VPN connection between sites, enabling organizations to establish a robust network infrastructure.

FlexVPN Site-to-Site Smart Defaults offers several key features and benefits that contribute to improved network security. Firstly, it provides secure cryptographic algorithms that protect data transmission, ensuring the confidentiality and integrity of sensitive information. Additionally, it supports various authentication methods, such as digital certificates and pre-shared keys, further enhancing the overall security of the VPN connection. The feature also allows for easy scalability, enabling organizations to expand their network infrastructure without compromising security.

Example WAN Technology: FlexVPN IKEv2 Routing

Understanding FlexVPN

FlexVPN, short for Flexible VPN, is a versatile framework offering various VPN solutions. It provides a secure and scalable approach to establishing Virtual Private Networks (VPNs) over various network infrastructures. With its flexibility, it allows for seamless integration and interoperability across different platforms and devices.

IKEv2, or Internet Key Exchange version 2, is a secure and efficient protocol for establishing and managing VPN connections. It boasts numerous advantages, including its robust security features, ability to handle network disruptions, and support for rapid reconnection. IKEv2 is highly regarded for its ability to maintain stable and uninterrupted VPN connections, making it an ideal choice for FlexVPN.

a. Enhanced Security: FlexVPN IKEv2 Routing offers advanced encryption algorithms and authentication methods, ensuring the confidentiality and integrity of data transmitted over the VPN.

b. Scalability: With its flexible architecture, FlexVPN IKEv2 Routing effortlessly scales to accommodate growing network demands, making it suitable for small—to large-scale deployments.

c. Dynamic Routing: One of FlexVPN IKEv2 Routing’s standout features is its support for dynamic routing protocols, such as OSPF and EIGRP. This enables efficient and dynamic routing of traffic within the VPN network.

d. Seamless Failover: FlexVPN IKEv2 Routing provides automatic failover capabilities, ensuring uninterrupted connectivity even during network disruptions or hardware failures.

Understanding MPLS (Multi-Protocol Label Switching)

MPLS serves as the foundation for MPLS VPNs. It is a versatile and efficient routing technique that uses labels to forward data packets through a network. By assigning labels to packets, MPLS routers can make fast-forwarding decisions based on the labels, reducing the need for complex and time-consuming lookups in routing tables. This results in improved network performance and scalability.

Understanding MPLS LDP

MPLS LDP is a crucial component in establishing label-switched paths within MPLS networks. MPLS LDP facilitates efficient packet forwarding and routing by enabling the distribution of labels and creating forwarding equivalency classes. Let’s take a closer look at how MPLS LDP operates.

One of the fundamental aspects of MPLS LDP is label distribution. Through signaling protocols, MPLS LDP ensures that labels are assigned and distributed across network nodes. This enables routers to make forwarding decisions based on labels, resulting in streamlined and efficient data transmission.

In MPLS LDP, labels serve as the building blocks of label-switched paths. These paths allow routers to forward packets based on labels rather than traditional IP routing. Additionally, MPLS LDP employs forwarding equivalency classes (FECs) to group packets with similar characteristics, further enhancing network performance.

MPLS Virtual Private Networks (VPNs) Explained

VPNs provide secure communication over public networks by creating a private tunnel through which data can travel. They employ encryption and tunneling protocols to protect data from eavesdropping and unauthorized access. MPLS VPNs utilize this VPN concept to establish secure connections between geographically dispersed sites or remote users.

MPLS VPN Components

Customer Edge (CE) Router: The CE router acts as the entry and exit point for customer networks. It connects to the provider network and exchanges routing information. It encapsulates customer data into MPLS packets and forwards them to the provider network.

Provider Edge (PE) Router: The PE router sits at the edge of the service provider’s network and connects to the CE routers. It acts as a bridge between the customer and provider networks and handles the MPLS label switching. The PE router assigns labels to incoming packets and forwards them based on the labels’ instructions.

Provider (P) Router: P routers form the backbone of the service provider’s network. They forward MPLS packets based on the labels without inspecting the packet’s content, ensuring efficient data transmission within the provider’s network.

Virtual Routing and Forwarding (VRF) Tables: VRF tables maintain separate routing instances within a single PE router. Each VRF table represents a unique VPN and keeps the customer’s routing information isolated from other VPNs. VRF tables enable the PE router to handle multiple VPNs concurrently, providing secure and independent communication channels.

Use Case – DMVPN Single Hub, Dual Cloud

Single Hub, Dual Cloud is a specific configuration within the DMVPN architecture. In this setup, a central hub device acts as the primary connection point for branch offices while utilizing two separate cloud providers for redundancy and load balancing. This configuration offers several advantages, including improved availability, increased bandwidth, and enhanced failover capabilities.

1. Enhanced Redundancy: By leveraging two cloud providers, organizations can achieve high availability and minimize downtime. If one cloud provider experiences an issue or outage, the traffic can seamlessly be redirected to the alternate provider, ensuring uninterrupted connectivity.

2. Load Balancing: Distributing network traffic across two cloud providers allows for better resource utilization and improved performance. Organizations can optimize their bandwidth usage and mitigate potential bottlenecks.

3. Scalability: Single Hub, Dual Cloud DMVPN allows organizations to easily scale their network infrastructure by adding more branch offices or cloud providers as needed. This flexibility ensures that the network can adapt to changing business requirements.

4. Cost Efficiency: Utilizing multiple cloud providers can lead to cost savings through competitive pricing and the ability to negotiate better service level agreements (SLAs). Organizations can choose the most cost-effective options while maintaining the desired level of performance and reliability.

The role of SDN

With software-defined networking (SDN), network configurations can be dynamic and programmatically optimized, improving network performance and monitoring more like cloud computing than traditional network management. By disassociating the forwarding of network packets from routing (control plane), SDN can be used to centralize network intelligence within a single network component by improving the static architecture of traditional networks.

Controllers make up the control plane of an SDN network, which contains all of the network’s intelligence. They are considered the brains of the network. Security, scalability, and elasticity are some of the drawbacks of centralization.

Since OpenFlow’s emergence in 2011, SDN was commonly associated with remote communication with network plane elements to determine the path of network packets across network switches. Additionally, proprietary network virtualization platforms, such as Cisco Systems’ Open Network Environment and Nicira’s, use the term.

The SD-WAN technology is used in wide area networks (WANs)

SD-WAN, short for Software-Defined Wide Area Networking, is a transformative approach to network connectivity. Unlike traditional WAN, which relies on hardware-based infrastructure, SD-WAN utilizes software and cloud-based technologies to connect networks over large geographic areas securely. By separating the control plane from the data plane, SD-WAN provides centralized management and enhanced flexibility, enabling businesses to optimize their network performance.

Transport Independance: Hybrid WAN

The hybrid WAN concept was born out of this need. An alternative path that applications can take across a WAN environment is provided by hybrid WAN, which involves businesses acquiring non-MPLS networks and adding them to their LANs. Business enterprises can control these circuits, including routing and application performance. VPN tunnels are typically created over the top of these circuits to provide secure transport over any link. 4G/LTE, L2VPN, commodity broadband Internet, and L2VPN are all examples of these types of links.

As a result, transport independence is achieved. In this way, any transport type can be used under the VPN, and deterministic routing and application performance can be achieved. These commodity links can transmit some applications rather than the traditionally controlled L3VPN MPLS links provided by service providers.

SDN and APIs

WAN SDN is a modern approach to network management that uses a centralized control model to manage, configure, and monitor large and complex networks. It allows network administrators to use software to configure, monitor, and manage network elements from a single, centralized system. This enables the network to be managed more efficiently and cost-effectively than traditional networks.

SDN uses an application programming interface (API) to abstract the underlying physical network infrastructure, allowing for more agile network control and easier management. It also enables network administrators to rapidly configure and deploy services from a centralized location. This enables network administrators to respond quickly to changes in traffic patterns or network conditions, allowing for more efficient use of resources.

Scalability and Automation

SDN also allows for improved scalability and automation. Network administrators can quickly scale up or down the network by leveraging automated scripts depending on its current needs. Automation also enables the network to be maintained more rapidly and efficiently, saving time and resources.

Before you proceed, you may find the following posts helpful:

WAN SDN

A Deterministic Solution

Technology typically starts as a highly engineered, expensive, deterministic solution. As the marketplace evolves and competition rises, the need for a non-deterministic, inexpensive solution comes into play. We see this throughout history. First, mainframes were/are expensive, and with the arrival of a microprocessor personal computer, the client/server model was born. The Static RAM ( SRAM ) technology was replaced with cheaper Dynamic RAM ( DRAM ). These patterns consistently apply to all areas of technology.

Finally, deterministic and costly technology is replaced with intelligent technology using redundancy and optimization techniques. This process is now appearing in Wide Area Networks (WAN). Now, we are witnessing changes to routing space with the incorporation of Software Defined Networking (SDN) and BGP (Border Gateway Protocol). By combining these two technologies, companies can now perform intelligent routing, aka SD-WAN path selection, with an SD WAN Overlay

SD-WAN Path Selection

SD-WAN path selection is essential to a Software-Defined Wide Area Network (SD-WAN) architecture. SD-WAN path selection selects the most optimal network path for a given application or user. This process is automated and based on user-defined criteria, such as latency, jitter, cost, availability, and security. As a result, SD-WAN can ensure that applications and users experience the best possible performance by making intelligent decisions on which network path to use.

When selecting the best path for a given application or user, SD-WAN looks at the quality of the connection and the available bandwidth. It then looks at the cost associated with each path. Cost can be a significant factor when selecting a path, especially for large enterprises or organizations with multiple sites.

SD-WAN can also prioritize certain types of traffic over others. This is done by assigning different weights or priorities for various kinds of traffic. For example, an organization may prioritize voice traffic over other types of traffic. This ensures that voice traffic has the best possible chance of completing its journey without interruption.

Diagram: SD WAN traffic steering. Source Cisco.

Critical Considerations for Implementation:

Network Security:

When adopting WAN SDN, organizations must consider the potential security risks associated with software-defined networks. Robust security measures, including authentication, encryption, and access controls, should be implemented to protect against unauthorized access and potential vulnerabilities.

Staff Training and Expertise:

Implementing WAN SDN requires skilled network administrators proficient in configuring and managing the software-defined network infrastructure. Organizations must train and upskill their IT teams to ensure successful implementation and ongoing management.

Real-World Use Cases:

Multi-Site Connectivity:

WAN SDN enables organizations with multiple geographically dispersed locations to connect their sites seamlessly. Administrators can prioritize traffic, optimize bandwidth utilization, and ensure consistent network performance across all locations by centrally controlling the network.

Cloud Connectivity:

With the increasing adoption of cloud services, WAN SDN allows organizations to connect their data centers to public and private clouds securely and efficiently. This facilitates smooth data transfers, supports workload mobility, and enhances cloud performance.

Disaster Recovery:

WAN SDN simplifies disaster recovery planning by allowing organizations to reroute network traffic dynamically during a network failure. This ensures business continuity and minimizes downtime, as the network can automatically adapt to changing conditions and reroute traffic through alternative paths.

The Rise of WAN SDN

The foundation for business and cloud services are crucial elements of business operations. The transport network used for these services is best efforts, weak, and offers no guarantee of an acceptable delay. More services are being brought to the Internet, yet the Internet is managed inefficiently and cheaply.

Every Autonomous System (AS) acts independently, and there is a price war between transit providers, leading to poor quality of transit services. Operating over this flawed network, customers must find ways to guarantee applications receive the expected level of quality.

Border Gateway Protocol (BGP), the Internet’s glue, has several path selection flaws. The main drawback of BGP is the routing paradigm relating to the path-selection process. BGP default path selection is based on Autonomous System (AS) Path length; prefer the path with the shortest AS_PATH. It misses the shape of the network with its current path selection process. It does not care if propagation delay, packet loss, or link congestion exists. It resulted in long path selection and utilizing paths potentially experiencing packet loss.

Example: WAN SDN with Border6

Border6 is a French company that started in 2012. It offers non-stop internet and an integrated WAN SDN solution, influencing BGP to perform optimum routing. It’s not a replacement for BGP but a complementary tool to enhance routing decisions. For example, it automates changes in routing in cases of link congestion/blackouts.

“The agile way of improving BGP paths by the Border 6 tool improves network stability” Brandon Wade, iCastCenter Owner.

As the Internet became more popular, customers wanted to add additional intelligence to routing. Additionally, businesses require SDN traffic optimizations, as many run their entire service offerings on top of it.

What is non-stop internet?

Border6 offers an integrated WAN SDN solution with BGP that adds intelligence to outbound routing. A common approach when designing SDN in real-world networks is to prefer that SDN solutions incorporate existing field testing mechanisms (BGP) and not reinvent all the wheels ever invented. Therefore, the border6 approach to influence BGP with SDN is a welcomed and less risky approach to implementing a greenfield startup. In addition, Microsoft and Viptela use the SDN solution to control BGP behavior.

Border6 uses BGP to guide what might be reachable. Based on various performance metrics, they measure how well paths perform. They use BGP to learn the structure of the Internet and then run their algorithms to determine what is essential for individual customers. Every customer has different needs to reach different subnets. Some prefer costs; others prefer performance.

They elect several interesting “best” performing prefixes, and the most critical prefixes are selected. Next, they find probing locations and measure the source with automatic probes to determine the best path. All these tools combined enhance the behavior of BGP. Their mechanism can detect if an ISP has hardware/software problems, drops packets, or rerouting packets worldwide.

Thousands of tests per minute

The Solution offers the best path by executing thousands of tests per minute and enabling results to include the best paths for packet delivery. Outputs from the live probing of path delays and packet loss inform BGP on which path to route traffic. The “best path” is different for each customer. It depends on the routing policy the customer wants to take. Some customers prefer paths without packet loss; others wish to cheap costs or paths under 100ms. It comes down to customer requirements and the applications they serve.

BGP – Unrelated to Performance

Traditionally, BGP gets its information to make decisions based on data unrelated to performance. Broder 6 tries to correlate your packet’s path to the Internet by choosing the fastest or cheapest link, depending on your requirements.

They are taking BGP data service providers and sending them as a baseline. Based on that broad connectivity picture, they have their measurements – lowest latency, packets lost, etc.- and adjust the data from BGP to consider these other measures. They were, eventually, performing optimum packet traffic forwarding. They first look at Netflow or Sflow data to determine what is essential and use their tool to collect and aggregate the data. From this data, they know what destinations are critical to that customer.

BGP for outbound | Locator/ID Separation Protocol (LISP) for inbound

Border6 products relate to outbound traffic optimizations. It can be hard to influence inbound traffic optimization with BGP. Most AS behave selfishly and optimize the traffic in their interest. They are trying to provide tools that help AS optimize inbound flows by integrating their product set with the Locator/ID Separation Protocol (LISP). The diagram below displays generic LISP components. It’s not necessarily related to Border6 LISP design.

LISP decouples the address space so you can optimize inbound traffic flows. Many LISP uses cases are seen with active-active data centers and VM mobility. It decouples the “who” and the “where,” which allows end-host addressing not to correlate with the actual host location. The drawback is that LISP requires endpoints that can build LISP tunnels.

Currently, they are trying to provide a solution using LISP as a signaling protocol between Border6 devices. They are also working on performing statistical analysis for data received to mitigate potential denial-of-service (DDoS) events. More DDoS algorithms are coming in future releases.

Closing Points: On WAN SDN

At its core, WAN SDN separates the control plane from the data plane, facilitating centralized network management. This separation allows for dynamic adjustments to network configurations, providing businesses with the agility to respond to changing conditions and demands. By leveraging software to control network resources, organizations can achieve significant improvements in performance and cost-effectiveness.

One of the primary advantages of WAN SDN is its ability to optimize network traffic and improve bandwidth utilization. By intelligently routing data, WAN SDN minimizes latency and enhances the overall user experience. Additionally, it simplifies network management by providing a single, centralized platform to control and configure network policies, reducing the complexity and time required for network maintenance.

Summary: WAN SDN

In today’s digital age, where connectivity and speed are paramount, traditional Wide Area Networks (WANs) often fall short of meeting the demands of modern businesses. However, a revolutionary solution that promises to transform how we think about and utilize WANs has emerged. Enter Software-Defined Networking (SDN), a paradigm-shifting approach that brings unprecedented flexibility, efficiency, and control to WAN infrastructure.

Understanding SDN

At its core, SDN is a network architecture that separates the control plane from the data plane. By decoupling network control and forwarding functions, SDN enables centralized management and programmability of the entire network, regardless of its geographical spread. Traditional WANs relied on complex and static configurations, but SDN introduced a level of agility and simplicity that was previously unimaginable.

Benefits of SDN for WANs

Enhanced Flexibility

SDN empowers network administrators to dynamically configure and customize WANs based on specific requirements. With a software-based control plane, they can quickly implement changes, allocate bandwidth, and optimize traffic routing, all in real time. This flexibility allows businesses to adapt swiftly to evolving needs and drive innovation.

Improved Efficiency

By leveraging SDN, WANs can achieve higher levels of efficiency through centralized management and automation. Network policies can be defined and enforced holistically, reducing manual configuration efforts and minimizing human errors. Additionally, SDN enables the intelligent allocation of network resources, optimizing bandwidth utilization and enhancing overall network performance.

Enhanced Security

Security threats are a constant concern in any network infrastructure. SDN brings a new layer of security to WANs by providing granular control over traffic flows and implementing sophisticated security policies. With SDN, network administrators can easily monitor, detect, and mitigate potential threats, ensuring data integrity and protecting against unauthorized access.

Use Cases and Implementation Examples

Dynamic Multi-site Connectivity

SDN enables seamless connectivity between multiple sites, allowing businesses to establish secure and scalable networks. With SDN, organizations can dynamically create and manage virtual private networks (VPNs) across geographically dispersed locations, simplifying network expansion and enabling agile resource allocation.

Cloud Integration and Hybrid WANs

Integrating SDN with cloud services unlocks a whole new level of scalability and flexibility for WANs. By combining SDN with cloud-based infrastructure, organizations can easily extend their networks to the cloud, access resources on demand, and leverage the benefits of hybrid WAN architectures.

Conclusion:

With its ability to enhance flexibility, improve efficiency, and bolster security, SDN is ushering in a new era for Wide-Area Networks (WANs). By embracing the power of software-defined networking, businesses can overcome the limitations of traditional WANs and build robust, agile, and future-proof network infrastructures. It’s time to embrace the SDN revolution and unlock the full potential of your WAN.

Viptela Software Defined WAN (SD-WAN)

May 5, 2015

by Matt Conran Blog

Viptela SD WAN

Why can’t enterprise networks scale like the Internet? What if you could virtualize the entire network?

Wide Area Network (WAN) connectivity models follow a hybrid approach, and companies may have multiple types – MPLS and the Internet. For example, branch A has remote access over the Internet, while branch B employs private MPLS connectivity. Internet and MPLS have distinct connectivity models, and different types of overlay exist for the Internet and MPLS-based networks.

The challenge is to combine these overlays automatically and provide a transport-agnostic overlay network. The data consumption model in enterprises is shifting. Around 70% of data is; now Internet-bound, and it is expensive to trombone traffic from defined DMZ points. Customers are looking for topological flexibility, causing a shift in security parameters. Topological flexibility forces us to rethink WAN solutions for tomorrow’s networks and leads towards Viptela SD-WAN.

Before you proceed, you may find the following helpful:

Solution: Viptela SD WAN

Viptela created a new overlay network called Secure Extensible Network (SEN) to address these challenges. For the first time, encryption is built into the solution. Security and routing are combined into one solution. Enables you to span environments, anywhere-to-anywhere in a secure deployment. This type of architecture is not possible with today’s traditional networking methods.

Founded in 2012, Viptela is a Virtual Private Network (VPN) company utilizing concepts of Software Defined Networking (SDN) to transform end-to-end network infrastructure. Based in San Jose, they are developing an SDN Wide Area Network (WAN) product offering any-to-any connectivity with features such as application-aware routing, service chaining, virtual Demilitarized Zone (DMZ), and weighted Equal Cost Multipath (ECMP) operating on different transports.

The key benefit of Viptela is any-to-any connectivity product offering. Connectivity was previously found in Multiprotocol Label Switching (MPLS) networks. They purely work on the connectivity model and not security frameworks. They can, however, influence-traffic paths to and from security services.

Ubiquitous data plane

MPLS was attractive because it had a single control plane and a ubiquitous data plane. As long as you are in the MPLS network, connection to anyone is possible. Granted, you have the correct Route Distinguisher (RD) and Route Target (RT) configurations. But why can’t you take this model to Wide Area Network? Invent a technology that can create a similar model and offer ubiquitous connectivity regardless of transport type ( Internet, MPLS ).

Why Viptela SDN WAN?

The business today wants different types of connectivity modules. When you map service to business logic, the network/service topology is already laid out. It’s defined. Services have to follow this topology. Viptela is changing this concept by altering the data and control plane connectivity model using SDN to create an SDN WAN technology.

SDN is all about taking intensive network algorithms out of the hardware. Previously, in traditional networks, this was in individual hardware devices using control plane points in the data path. As a result, control points may become congested (for example – OSPF max neighbors reached). Customers lose capacity on the control plane front but not on the data plane. SDN is moving the intensive computation to off-the-shelf servers. MPLS networks attempt to use the same concepts with Route-Reflector (RR) designs.

They started to move route reflectors off the data plane to compute the best-path algorithms. Route reflectors can be positioned anywhere in the network and do not have to sit on the data path. Controller-based SDN approach, you are not embedding the control plane in the network. The controller is off the path. Now, you can scale out and SDN frameworks centrally provision and push policy down to the data plane.

Viptela can take any circuit and provide the ubiquitous connectivity MPLS provided, but now, it’s based on a policy with a central controller. Remote sites can have random transport methods. One leg could be the Internet, and the other could be MPLS. As long as there is an IP path between endpoint A and the controller, Viptela can provide the ubiquitous data plane.

Viptela SD WAN and Secure Extensible Network (SEN)

Managed overlay network

If you look at the existing WAN, it is two-part: routing and security. Routing connects sites, and security secures transmission. We have too many network security and policy configuration points in the current model. SEN allows you to centralize control plane security and routing, resulting in data path fluidity. The controller takes care of routing and security decisions.

It passes the relevant information between endpoints. Endpoints can pop up anywhere in the network. All they have to do is set up a control channel for the central controller. This approach does not build excessive control channels, as the control channel is between the controller and endpoints. Not from endpoint to endpoint. The data plane can flow based on the policy in the center of the network.

Viptela SD WAN: Deployment considerations

Deployment of separate data plane nodes at the customer site is integrated into existing infrastructure at Layer 2 or 3. So you can deploy incrementally, starting with one node and ending with thousands. It is so scalable because it is based on routed technology. The model allows you to deploy, for example, a guest network and then integrate it further into your network over time. Internally they use Border Gateway Protocol (BGP). One the data plane, they use standard IPSec between endpoints. It also works over Network Address Translation (NAT), meaning IPSec over UDP.

When an attacker gets access to your network, it is easy for them to reach the beachhead and hop from one segment to another. Viptela enables per-segment encryption, so even if they get to one segment, they will not be able to jump to another. Key management on a global scale has always been a challenge. Viptela solves this with a propitiatory distributed manager based on a priority system. Currently, their key management solution is not open to the industry.

SDN controller

You have a controller and VPN termination points i.e data plane points. The controller is the central management piece that assigns the policy. Data points are modules that are shipped to customer sites. The controller allows you to dictate different topologies for individual endpoint segments. Similar to how you influence-routing tables with RT in MPLS.

The control plane is at the controller.

Data plane module

Data plane modules are located at the customer site. They connect this data plane module, which could be a PE hand-off to the internal side of the network. The data plane module must be in the data plane path on the customer site. Internal side, they discover the routing protocols and participate in prefix learning. At Layer 2, they discover the VLANs. Their module can either be the default gateway or perform the router neighbor relationship function. WAN side, data plane module registers uplink IP address to WAN controller/orchestration system. The controller builds encrypted tunnels between the data endpoints. The encrypted control channels are only needed when you build over untrusted third parties.

If the problem occurs with controller connectivity, the on-site module can stop being the default gateway and usually participate in Layer 3 forwarding for existing protocols. It backs off from being the primary router for off-net traffic. It’s like creating VRF for different businesses and default routes for each VRF with a single peering point to the controller; Policy-Based Routing (PBR) for each VRF for data plane activity. The PBR is based on information coming from the controller. Each control segment can have a separate policy (for example – modifying the next hop). From a configuration point of view, you need an IP on the data plane module and the remote controller IP. The controller pushes down the rest.

Viptela SD WAN: Use cases

For example, you have a branch office with three distinct segments, and you want each endpoint to have its independent topology. The topology should be service driven, and the service should not follow existing defined topology. Each business should depict how they want their business to connect to the network team should not say this is how the topology is, and you must obey our topology.

From a carrier’s perspective, they can expand their MPLS network to areas they do not have a physical presence. And bring customers with this secure overlay to their closest pop where they have an MPLS peering. MPLS providers can expand their footprint to areas where they do not have service. If MPLS has customers in region X and wants to connect to the customer in region Y, they can use Viptela. Having those different data plane endpoints through a security framework would be best before entering the MPLS network.

Viptela allows you to steer traffic based on the SLA requirements of the application, aka Application-Aware Routing. For example, if you have two sites with dual connectivity to MPLS and Internet, data plane modules (located at customer sites) nodes can steer traffic over either the MPLS or Internet transport based on end-to-end latency or drops. They do this by maintaining the real-time loss, latency, and jitter characteristics and then applying policies on the centralized controller. As a result, critical traffic is always steered to the most reliable link. This architecture can scale to 1000 nodes in a full mesh topology.

BGP-Based SDN

Highlights: BGP-Based SDN

Understanding BGP and SDN

Knowledge Check: Prefer EBGP over iBGP

## The Role of BGP in Traditional Networking ##

Critical Components of BGP SDN:

Benefits of BGP SDN:

Use Cases for BGP SDN:

BGP Technologies in BGP SDN

Understanding BGP Route Reflection

Understanding BGP Multipath

SDN and BGP

Augmented Model

The Role of SDN

BGP and OpenFlow

BGP Add Path Feature

BGP-Based SDN

What is BGP?

Highlighting BGP-based SDN

Creating an SDN architecture

Why use BGP?

The use of open-source BGP daemons

IGP to the controller?

Introducing BGP-LS

BGP scale-out architectures

Final Points: BGP-Based SDN

Summary: BGP-Based SDN

VIPTELA SD-WAN

Problem Statement

Traditional Segmentation

MPLS Challenges

Applications Must Fit A Certain Topology

Viptela SD-WAN & Topologies Per Application

SD-WAN Topologies

Viptela SD-WAN: Predictable Application Performance

WAN SDN

Highlights: WAN SDN

Discussing WAN SDN

**Application Challenges**

**WAN SLA**

WAN SDN Technology: DMVPN

DMVPN over IPSec

Example WAN Techniques:

Understanding Virtual Routing and Forwarding

Understanding Policy-Based Routing

Example SD WAN Product: Cisco Meraki

Performance at the WAN Edge

Understanding Performance-Based Routing

WAN Performance Parameters

Understanding TCP MSS

Example WAN Technology: DMVPN Phase 3

Example WAN Technology: FlexVPN Site-to-Site Smart Defaults

Example WAN Technology: FlexVPN IKEv2 Routing

Understanding MPLS (Multi-Protocol Label Switching)

MPLS Virtual Private Networks (VPNs) Explained

Use Case – DMVPN Single Hub, Dual Cloud

The role of SDN

Transport Independance: Hybrid WAN

SDN and APIs

Scalability and Automation

WAN SDN

A Deterministic Solution

**SD-WAN Path Selection**

Critical Considerations for Implementation:

Real-World Use Cases:

The Rise of WAN SDN

Example: WAN SDN with Border6

What is non-stop internet?

Thousands of tests per minute

**BGP – Unrelated to Performance**

BGP for outbound | Locator/ID Separation Protocol (LISP) for inbound

Closing Points: On WAN SDN

Summary: WAN SDN

Viptela SD WAN

Solution: Viptela SD WAN

Ubiquitous data plane

Viptela SD WAN and Secure Extensible Network (SEN)

Managed overlay network

Quick Links

Contact

Application Challenges

WAN SLA

SD-WAN Path Selection

BGP – Unrelated to Performance